文档介绍：硕士学位论文
摘要
偏振模色散(PMD: polarization mode dispersion)被认为是光纤通信系统特别
是波分复用(WDM: wavelength division multiplexing)系统传输容量和传输性能的
最终限制因素,如何消除其影响就成为了高速率和长距离光纤通信发展的关键。
然而,由于 PMD 随着频率和环境温度等条件而随机变化,使得 PMD 的补偿非常
困难。本论文主要对 WDM 系统中偏振模色散自适应补偿技术做了研究,具体内容
包括以下两个方面:
采用分布傅立叶变换法求解耦合非线性薛定谔方程,数值模拟了考虑 PMD
和非线性效应情况下,8 × 40 Gbit/ s 的 WDM 系统传输 100km 后的眼图以及 DOP
值。分析 PMD、非线性效应等对 WDM 系统的综合影响,得到如下结论:PMD
对 WDM 系统每个信道的影响是不同的,即每个信道的眼图张开度不同、DOP 值
不同。这个结论为后面的 WDM 系统中 PMD 自适应补偿提供了理论依据。
依据波分复用系统的特点,采用最坏信道补偿方案对 WDM 系统中 PMD 进
行了自适应补偿,即只对性能最差的几个信道进行动态补偿。该方案中的补偿器
采用三阶段 PMD 补偿器,搜索算法采用粒子群优化算法,反馈信号采用 DOP。
数值模拟得到了补偿后性能最差的几个信道的眼图及 DOP 值。数值模拟得到的补
偿结果表明,补偿后性能最差的几个信道的 DOP 值都得到提高,并且眼图张开度
也有所增大。而在 WDM 系统中,信道的 DOP 值一般不能小于。根据补偿
后的 DOP 值可知,经过补偿后所有补偿信道的 DOP 值都大于。这说明该补
偿方案能有效的对 WDM 系统的 PMD 进行自适应补偿,改善系统的性能。

关键词:超高速光通信;偏振模色散自适应补偿;波分复用;最坏信道补偿方案
I
WDM 系统中偏振模色散自适应补偿的研究
Abstract
Polarization mode dispersion (PMD) is regarded as a severe, ultimate limitation
in munication systems, especially in wavelength division multiplexing
(WDM) systems. Therefore how to reduce its impacts is a vital subject in development
of high-speed and long haul munication systems. However, it is very
difficult pensate the PMD effect because of its stochastic feature. The PMD
compensation method in WDM munication systems and the adaptive
high-order pensation techniques are mainly discussed. Above all, the
research works in the dissertation are summed up as following:
In this thesis the coupled nonlinear Schrödinger equation is solved by means of
split-step Fourier transform. The coupled nonlinear Schrödinger equation in
eight-channel WDM systems is numerically solved and the effects of PMD on WDM
systems are analyzed. The eye diagrams and the degrees of polarization (DOP) after
propagating 100km are obtained. Conclusion is that the influence of PMD on each
channel is different, which would be considered with the development of adaptive
compensation of PMD in WDM optical munication